The goal of this contract is to provide support of National Toxicology Program (NTP) hazard identification activities targeted toward the prevention of diseases or adverse effects caused by environmental exposure to chemical or physical agents. To carry out its mission to evaluate environmental substances of public health concern by developing and applying tools of modern toxicology and molecular biology, the NTP organizes and conducts a comprehensive research and testing program focused on determining potential human health hazards of exposures to chemical, biological or physical substances or mixtures of substances. The nomination and selection of substances for study by the NTP is critical to the effective long-term operation of the program and helps to ensure that NTP resources are being used to address priority public health needs. Within the NIEHS, the NTP Office of Nomination and Selection serves as the focal point for coordinating the nomination and selection process and providing supporting documentation for the evaluation and selection of substances nominated for study. This contract provides administrative and scientific support for the preparation of information materials and background documents on substances or issues under consideration for toxicological study by the NTP. Substances evaluated by the NTP include chemical, physical and biological agents to which humans are likely to be exposed and for which there is inadequate toxicity information to accurately estimate potential human health hazards and risks. The contractor utilizes public and proprietary databases and other information sources to comprehensively search and identify the existing information on substances under consideration. The data and information gathered in the literature searches are used to prepare brief summaries of the literature identified and a written review document (Toxicological Summary Report) containing information on physical and chemical properties, production levels and processes, uses, human exposure, regulatory status, human and environmental health effects, experimental toxicology studies, and structure-activity relationships. These reports are used in the formal open public process for the review and selection of substances for study by the NTP and for the design of NTP toxicology studies. Specifically, the reports are provided as supporting documents to each committee in the nomination review process (Interagency Committee for Chemical Evaluation and Coordination [ICCEC], NTP Board of Scientific Counselors, and the NTP Executive Committee). The supporting documents are made publicly available via the NTP web site during the nomination review process (e.g. see http://ntp.niehs.nih.gov/go/34146) and are subsequently maintained on the NTP web site as nomination background information (e.g. see http://ntp.niehs.nih.gov/go/18546). The information and documents developed though this contract, along with the data generated by the various NTP research and testing programs, are also used in the preparation of NTP Technical Reports. The NTP nomination review and selection process is described in more detail at http://ntp.niehs.nih.gov/go/156.